L2 Access Switches

L2 access switches connect the StarlingX hosts to the different networks. Proper configuration of the access ports is necessary to ensure proper traffic flow.

One or more L2 switches can be used to connect the StarlingX hosts to the different networks. When sharing a single L2 switch you must ensure proper isolation of network traffic. A sample configuration for a shared L2 switch could include:

  • one port-based VLAN for the internal management network with internal cluster host network sharing this same L2 network (default configuration)

  • one port-based VLAN for the OAM network

  • one or more sets of VLANs for additional networks for external network connectivity

When using multiple L2 switches, there are several deployment possibilities:

  • A single L2 switch for the internal management cluster host and OAM networks. Port or MAC-based network isolation is mandatory.

  • An additional L2 switch for the one or more additional networks for external network connectivity.

  • Redundant L2 switches to support link aggregation, using either a failover model, or VPC for more robust redundancy. For more information, see Redundant Top-of-Rack Switch Deployment Considerations.

Switch ports that send tagged traffic are referred to as trunk ports. They participate in STP from the moment the link goes up, which results in a several second delay before the trunk port moves to the forwarding state. This delay will impact services such as DHCP and PXE that are used during regular operations of StarlingX.

You must consider configuring the switch ports, to which the management interfaces are attached, to transition to the forwarding state immediately after the link goes up. This option is referred to as a PortFast.

You should consider configuring these ports to prevent them from participating on any STP exchanges. This is done by configuring them to avoid processing inbound and outbound BPDU STP packets completely. Consult your switch’s manual for details.